>> I think that goes a little too far!
I agree.

>> My issue is that I have disabled the close so that I get better control over when to release the form and when to hide the form (I use hide so that I can reuse rather than recreate next time the form is needed as that's a lot faster.).

>> However client are complaining becuase they keep clicking on it even though it is greyed out.

I'm inclined to think that keeping Max & Min buttons while hiding the Close is hardly possible without substantial programming efforts.